Molar Masses assignment and quiz exam with 100% Correct answers already graded A+

A gas cylinder contains exactly 15 moles of oxygen gas (O2). How many molecules of oxygen are in the cylinder? 4.01 × 10^22 molecules 6.02 × 10^23 molecules 9.03 × 10^24 molecules 2.89 × 10^26 molecules 9.03 × 10^24 molecules A sample of sugar (C12H22O11) contains 1.505 × 1023 molecules of sugar. How many moles of sugar are present in the sample? Answer without doing any calculations. 0.25 mol 0.50 mol 1.00 mol 2.50 mol 0.25 mol Use the periodic table to determine the molar mass of each of the following elements. Potassium (K) Osmium (Os) Magnesium(Mg) The isotope lead-208 (208Pb) The isotope strontium-87 (87Sr) 39.10 g/mol 190.23 g/mol 54.94 g/mol 208 g/mol 87 g/mol Use the periodic table to calculate the molar mass of each of the following compounds. Give your answer to the correct number of significant figures. Ammonia (NH3) Lead(II) chloride (PbCl2) Acetic acid (CH3COOH) Magnesium hydroxide (Mg(OH)2) Iron(III) oxide (Fe2O3) 17.04 g/mol 278.10 g/mol 60.06 g/mol 58.33 g/mol 159.70 g/mol Use the periodic table to determine how many atoms of phosphorus (P) are in a sample that has a mass of 172.90 g. 3.48 × 10^21 atoms 1.97 × 10^22 atoms 3.36 × 10^24 atoms 1.04 × 10^26 atoms 3.36 × 10^24 atoms Select the correct mass for each of the samples described below. 3.01 × 1023 molecules H2O 8.32 × 1020 formula units CaBr2 1.93 × 1026 molecules XeF6 9.01 g 0.276 g 78,600 g Which is the formula mass of (NH4)2SO4? 96.07 amu 114.12 amu 116.17 amu 132.17 amu 132.17 amu The mole concept will most likely be used in... calculating the average height of a mountain range. measuring how many liters of gasoline are poured into a tank. determining how many ozone molecules are lost in the atmosphere. finding the mass of a piece of steak in a butcher shop. determining how many ozone molecules are lost in the atmosphere. Consider the equation below. Na+ + Cl- NaCl Which statement best describes the relationship between the substances in the equation? The number of sodium ions is equal to the number of formula units of salt. The number of sodium ions is less than the number of chloride ions. The number of chloride ions is less than the number of formula units of salt. The number of sodium ions is two times the number of formula units of salt. The number of sodium ions is equal to the number of formula units of salt. What is the molar mass of Al2(SO4)3? 150.03 g/mol 278.03 g/mol 342.17 g/mol 450.09 g/mol 342.17 g/mol Which best compares 1 mol of sodium chloride to 1 mol of aluminum chloride? Both have the same molar mass. Both have the same number of ions. Both are made up of 6.02 x 10^23 molecules. Both are made up of 6.02 x 10^23 formula units. Both are made up of 6.02 x 10^23 formula units. In a classroom, which comparison would a teacher most likely use for describing a mole? a cup of water and a liter of oil a dozen eggs and a dozen jellybeans a jar of jellybeans and a gram of salt crystals 20 marbles in a bag and 10 large ice cubes a dozen eggs and a dozen jellybeans How does the number of molecules in 1 mol of oxygen compare with the number of molecules in 1 mol of nitrogen? 1 mol of oxygen has fewer molecules. 1 mol of oxygen has more molecules. Each sample has the same number of molecules. The molecules cannot be compared without knowing the mass. Each sample has the same number of molecules. Which statement best describes a mole? It is 12 units of a given substance. It contains 6.02 x 10^23 grams of sodium chloride. It is the mass of 12 carbon atoms. It contains 6.02 x 10^23 particles of a given substance. It contains 6.02 x 10^23 particles of a given substance. Which is the molar mass of H2O? 10.02 g/mol 16.00 g/mol 17.01 g/mol 18.02 g/mol 18.02 g/mol